ABSTRACT
Background: he number of patients on warfarin therapy is rising steadily. Although warfarin is beneficial, it carries a high risk of bleeding, especially if the international normalized ratio (INR) values exceed 3.0. Currently, no warfarin initiation regimens have been developed for the Asian population, especially for Malaysians. Objective: This article describes the efficacy and safety of a new initiation regimen for warfarin among warfarin-naive patients. Method: Data were retrospectively collected from the ambulatory and inpatient settings. Results: A total of 165 patients who each had a target INR of 2.0 to 3.0 were included in the study. The mean age was 57.2 years and 94 patients were male. A total of 108 patients used Regimen 1 (5 mg/5 mg/3mg) and the rest of the patients used Regimen 2 (5 mg/3 mg/3 mg). Most patients used warfarin either for atrial fibrillation (52.1%) or for venous thromboembolism (29.7%). Overall, 88 of the patients had INR values above 50% from the baseline on Day 4. Additionally, 13 patients had INR values of >3.2, which required withholding and lower dose of warfarin. The predicted weekly maintenance warfarin dose (23 ± 0.5 mg/week) was found to have correlated closely with the actual maintenance dose (22.8 ± 0.5 mg/week; r 2 = 0.75). Nearly two thirds (70.3%) of the patients achieved the target INR on Day 11. Conclusion: The warfarin initiation regimens in this study was simple, safe, and suitable to be used in both ambulatory and inpatient settings for managing warfarin therapy.
ABSTRACT
There is a wide variation on the efficacy of three-factor Prothrombin Complex Concentrate (3F-PCC) in warfarin reversal. We aimed to determine the efficacy and safety of 3F-PCC in warfarin reversal. This multicentre prospective study analysed data from adult patients on warfarin who received 3F-PCC (Prothrombinex-VF®) for anticoagulation reversal between June 2019 to October 2020. Purposive sampling was used in this study. Study endpoints included target INR achievement, adverse drug reactions (ADRs), and in-hospital all-cause mortality. Logistic regression analyses were used to assess independent predictors of study endpoints. One-hundred thirty-seven patients with a median age of 68 (59-76) years were recruited, who were predominantly male (59.9%, n = 82). A total of 102 patients required 3F-PCC for life-threatening (40.9%, n = 56) and clinically significant bleeding (33.6%, n = 46). Initial INRs ranged from 1.55 to undetectable high (> 26). All patients had INR reduction, of which 62% (n = 85) achieved target INR, whereas 12.4% (n = 17) achieved INR below the target range. Median INR was reduced from 4.76 (3.14-8.32) to 1.54 (1.27-1.88) post-3F-PCC (p < 0.001). The use of adjunctive reversal agents and initial INR < 3.6 were the significant predictors for target INR achievement. Six (4.4%) ADRs were observed. Two (1.5%) cases with the suspected acute coronary syndrome were associated with mortality. Ischemic stroke occurred in one (0.7%) patient. The incidence of in-hospital all-cause mortality was 21.2% (n = 29). The rate of INR achievement was 62% in our study without apparent increased risk of thromboembolic events and in-hospital all-cause mortality.
Subject(s)
Anticoagulation Reversal , Aged , Anticoagulants/adverse effects , Blood Coagulation Factors , Factor IX , Female , Humans , International Normalized Ratio , Male , Middle Aged , Prospective Studies , Retrospective Studies , Warfarin/adverse effectsABSTRACT
INTRODUCTION: Non-vitamin K antagonist oral anticoagulants (NOACs), such as dabigatran and rivaroxaban, are now available for stroke prevention in patients with atrial fibrillation (AF) and are often clinically preferred over vitamin K antagonists (VKAs), such as warfarin. Data describing adherence and persistence to NOACs in real-life clinical practice in Malaysia are scarce. This study aimed to assess adherence and persistence to NOACs in patients with AF in two tertiary-care referral centers: Hospital Kuala Lumpur (HKL) and Hospital Serdang (HSDG). MATERIALS AND METHODS: This was a retrospective cohort study that included all patients with AF who were treated with NOACs (dabigatran or rivaroxaban) in HKL and HSDG. Data were obtained from medical records and pharmacy databases. Adherence was assessed using proportion of days covered (PDC) over a 1-year duration. High adherence was defined as PDC ≥80%. A gap of >60 days between two consecutive refills was used to define non-persistence. RESULT: There were 281 patients who met the inclusion criteria, with 54.1% (n = 152) male. There were 75.1% (n = 211) patients on dabigatran and others on rivaroxaban. Only 66.9% (n = 188) of patients achieved high adherence with PDC ≥80% and 69.8% (n = 196) were persistence with >60-day gap over 12 months. Adherence and persistence were both influenced by treatment center, whereas polypharmacy only influenced adherence. CONCLUSION: Overall adherence and persistence to NOACs were suboptimal and varied between treatment centers, potentially due to institution-specific administrative and clinical practice differences. Clinical care and outcomes can potentially be optimized by identifying factors affecting adherence and persistence and by implementing interventions to improving them.
